In an effort to bring problem solving approaches to medical education, Critical Concepts will develop a web-based human physiology simulator capable of reproducing patient responses in real time. This simulator will be based heavily on the prior simulator, SimBioSys ("Simulation of Biological Systems"). Developed under support from the NIH SBIR program, SimBioSys was designed to be the best simulation that can run on mainstream desktop computers. Still, the science in SimBioSys is limited by the available computational power of common desktop computers. Creating better mathematical models, able to simulate a richer variety of patient problems, and populating it with interesting clinical cases in a timely fashion thus requires a radical departure from prior approaches. The departure we propose is to develop a client-server real time model on the Internet, implementing the display and control features on a web client applet, and implementing the simulator calculations on a high performance server. Results of the mathematical simulation will be transmitted over the Internet a few seconds before they need to be displayed, and similarly user instructions will be communicated back from the client applet to the host program instance. By using the Internet and the web, we will provide the simulation as a service available at a low cost and effort to a wide group of users. We will extend the biological capabilities of the system, enabling us to simulate a much broader set of diseases. A new architecture will be required, new models will need to be developed, and new visual systems will need to be produced. The result will represent the next generation of educational patient simulation, and will benefit the greater medical community within the United States and throughout the Internet- connected world. PROPOSED COMMERCIAL APPLICATIONS: This development will permit the applicant organization to provide a novel educational service on a fee- for-service basis via the Internet.